Finding angles using potentiometers

[Metalheads81]

Hello,

I'm new to Labview, so be easy on me and my programming hack job. Thanks already for all of your previous posts, they have been helpful.

I'm using 2 - 10 turn potentiometers with slope of 1.33mV/degree to find the angles of two joints on our robot. I'm able to acquire the voltage and move the arms fine, but I would like to have preset heights that correspond to certain buttons.

A couple weeks ago I put together some code and verified that it worked. It compared the voltage and turned the motor a direction whether it was greater than or less than the desired voltage. After I got further along I converted buttons on the controller to an array, then array to number, and finally to a case. There I wanted to put different voltages in there for the different positions.

I then migrated all of the arm code to periodic tasks because I read that it is the preferred location for the robot tasks.

As of now, if I press a button to go to a location it will move in that direction, but pass it up. I might add that I implemented the voltage averaging of 5 bits, which seems to give a rather steady voltage. I've tried two different >, <, etc (case 1 & 2) sequences with no avail.

I then tried a PID.vi which seemed promising, but once again passed the desired location.

I probe the voltage in the vi and watch as the arm passes by the location, so theres definitely a valid voltage position being passed.

I assume that the case will repeat constantly until the button is released correct? Since its in periodic tasks does it reset every 1ms? Should this be done outside a timed structure?

Any help would be greatly appreciated. Thank you.